Using of additives inhibiting free radical processes is necessary at production of the lubricating oils. In given article such kind target compounds were obtained from the number of new 1-acyl-4-R-thiosemicarbazides which were synthesized on the base of 3- (4-hydroxy-3,5-di-tert-butyl) propanoic acid hydrazide. The starting hydrazide was prepared from commercially available methyl ester (methylox) by refluxing in ethanol with a slight excess of hydrazine hydrate for 8 h. The best yields of the 1-acyl-4-R-isothiocyanates were achieved by refluxing equimolar amounts of isothiocyanates and hydrazide in isopropanol for 4-5 h. Under these conditions the yield was 75-85%. At further cyclization of intermediates obtained at a first step in aqueous sodium hydroxide for 1.5 h the corresponding 3-acyl-4-R-1,2,4-triazolin-5-thiones were obtained with the yield of 70-90%. Also, this method has absolute advantages due to a simple isolation of target compounds. Based on the IR-spectroscopy data in middle region and 1H NMR spectroscopy it was established that the substances obtained in the crystalline state and in DMSO solution exist in a form of thiones. The composition of obtained substances was determined with elemental analysis whereas the structures of the synthesized compounds were confirmed with FT-IR spectroscopy methods, 1H NMR spectroscopy and mass spectrometry.Forcitation:Koshelev V.N., Ivanova L.V., Alasadi R.T.Kh., Primerova O.V. Synthesis of novel 4-R-1,2,4-triazolin-5-thiones containing space-hindered fragment of phenol. Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol. 2017. V. 60. N 3. P. 43-47.